Device for powering an electric motor of a motor vehicle

ABSTRACT

A device for electrically powering an electric motor of a motor vehicle includes first energy source, a second energy source, and a memory module in which is stored a value of a maximum operating power that can be provided by the second energy source. This maximum operating power value is a function of the cooling capacity of the second energy source.

The present invention relates to the field of electric or hybrid motorvehicles. The invention relates more particularly to power supplydevices intended to supply an appropriate electric power to the motor ofthese motor vehicles.

In electric or hybrid vehicles, the electric motor receives the electricpower needed for it to operate in particular from a main battery.

One of the issues in the development of electric vehicles is the travelrange of the vehicle. One solution contemplated to extend this range isto associate an additional energy source with the main battery, and itis in particular contemplated to associate a fuel cell system with themain battery. The electric motor may thus be supplied with power firstand foremost by the main battery and, if necessary, by the fuel cell,when the charge of the main battery is insufficient to continue to doso, in order to increase the range of the vehicle when the battery iscompletely discharged.

It may therefore be considered that the fuel cell and the main batteryare arranged in parallel with one another to allow separate electricpower supplies to the electric motor depending on the use case, theelectric motor being able to be supplied with power simultaneously bythe first energy source formed by the main battery and by the secondenergy source formed by the fuel cell system.

In such a configuration, in which the fuel cell system should beconsidered as a range extender of the main battery, the fuel cell maytherefore supply power directly to the electric motor, by supplementingthe main battery, and may also, if necessary, contribute to rechargingthe battery while the vehicle is in motion.

Another use of the fuel cell system is described in particular indocument DE102015011274, relating to the heating of the passengercompartment. This document refers to fuel cell control that is specificin that it may be modified on the basis of the detection of an outsidetemperature. More particularly, when the detected temperature is lowerthan a given value, the portion of the electric power supplied by thefuel cell is increased, in particular so as to be capable of respondingto the heating demands of the passenger compartment.

Indeed, in all cases, and in particular in the abovementioned cases inwhich the fuel cell system forms a range extender and is able to be usedto supply electrical energy to the motor of the vehicle, the productionof electrical energy by the fuel cell is accompanied by a significantincrease in temperature thereof. Within the fuel cell system, the fuelcell is thus associated with a cooling system that is specific theretoand that aims to evacuate calories through an exchange with outside air,via a heat exchanger arranged on the front face of the vehicle, forexample. In order to ensure the correct operation of the fuel cellregardless of the conditions in which the vehicle is traveling and inparticular regardless of the temperatures of the outside air,manufacturers may be forced to oversize the heat exchanger in order toensure that there are no problems with cooling the fuel cell, inparticular when outside temperatures are high.

The present invention falls within this context of fuel cell systemsused as a range extender and the problem of cooling these systems, andit proposes an electric power supply device for an electric motor of amotor vehicle, comprising at least one first energy source, at least onesecond energy source, and a control module for controlling the firstenergy source so as to supply a first electric power, on the one hand,and the second energy source so as to supply a second electric power, onthe other hand.

According to the invention, the electric power supply device ischaracterized in that the control module comprises a memory modulestoring a value of a maximum operating power able to be supplied by thesecond energy source, this maximum operating power value being dependenton the cooling capacity for the second energy source.

The power supply device that is the subject of the invention fallswithin the context of the use of a second energy source that makes itpossible to form a range extender, namely that this second source, andfor example a fuel cell generator, is housed on board the electricvehicle, being intended to increase the range thereof by ensuring therecharging of the first source and/or by supplying power directly to theelectric motor.

The power supply device according to the invention is special in that itmakes it possible to ensure that the use of the second energy source, asa range extender, takes place under conditions that do not risk leadingto overheating of this second energy source, without however needing tooversize a cooling system associated with this second source.

According to another feature of the invention, the power supply deviceis characterized in that the control module is configured to:

-   -   compare the value of the second electric power with the value of        the maximum operating power able to be supplied by the second        energy source,    -   modify, when the second electric power exceeds the maximum        operating power able to be supplied by the second energy source,        the controlling of the second source so as to reduce the value        of the second electric power to a value substantially equal to        that of the maximum operating power able to be supplied by the        second energy source, and    -   accordingly modify the controlling of the first source so as to        increase the first electric power supplied by the first energy        source.

According to one optional feature of the invention, the sum of thevalues of the first electric power and of the second electric power isequal to a target electric power intended to be supplied to the electricmotor. In other words, when the electric motor is supplied with powersimultaneously by the first electric source and the second electricsource, these two sources together generate a constant valuecorresponding to all or part of the electric power supplied to theelectric motor. According to the invention, the reduction in theelectric power supplied by the first energy source is then accompaniedby an increase in the electric power supplied by the second energysource in an equivalent proportion, such that the electric powersupplied to the electric motor by the power supply device according tothe invention remains at a constant value.

According to some features of the invention, taken alone or incombination:

-   -   the first energy source comprises at least one electric battery.        This battery is able to supply power directly to the electric        motor of the vehicle when it is sufficiently charged. This        battery may in particular be configured to be recharged by an        external energy source and/or by the second energy source. The        external energy source is an energy source needed to recharge        the main battery and located outside the vehicle, and it may for        example consist of a DC current from a supercharger or an AC        current from a power outlet in a home.    -   the second energy source comprises at least one fuel cell. This        fuel cell is able to supply power directly to the electric motor        of the vehicle, alternately or at the same time as the first        energy source. This fuel cell may in particular be configured to        be able to recharge the first energy source. The fuel cell        system comprises, in addition to the fuel cell, a hydrogen tank        and an air supply system. The fuel cell system comprises a fuel        cell cooling system, with in particular a heat exchanger able to        exchange calories with a cooling fluid, for example air outside        the vehicle.

According to one optional feature of the invention, the electric powersupply device may comprise at least one temperature sensor.

The control module may be configured to compare the detected temperaturewith a temperature threshold value, and to modify the controlling of theenergy sources when the detected temperature exceeds the thresholdvalue. In this way, and in the context that was recalled above of apower supply device according to the invention that is special in thatit makes it possible to ensure that the use of the second energy source,as a range extender, takes place under conditions that do not riskleading to overheating of this second energy source, without otherwisehaving to oversize a cooling system associated with this second source,the operation of the vehicle in specific environmental conditions, withhigh temperatures, is carried out through specific management of theelectric power supply in which priority is given to using the firstenergy source, and more particularly the main battery, whileprioritizing the operating safety of the second energy source ratherthan the range of the vehicle. It should however be noted that theoperation of the electric power supply device, in this case where theportion of electric power generated by the second source is reduced,continues to prioritize a supply of power to the electric motor both bythe first energy source and by the second energy source in order toextend the autonomy of the vehicle in spite of everything, in lesserproportions but effectively all the same.

According to another optional feature of the invention, the value of themaximum operating power able to be supplied by the second energy sourceis variable on the basis of the detected temperature.

The temperature detected by the temperature sensor may in particular bethe temperature outside the vehicle, but it should be noted that,without departing from the scope of the invention, the invention couldconsider a temperature inside the vehicle, and for example close to thefuel cell system.

The invention also relates to a motor vehicle comprising an electricmotor and an electric power supply device as has just been mentioned.

Another subject of the invention is a method for supplying an electricpower demanded by an electric power supply device for an electric motoras has just been mentioned above, the method comprising at least a stepof comparing the detected temperature with a temperature thresholdvalue, a step of comparing the second electric power demanded from thesecond energy source and the maximum operating power able to be suppliedby the second energy source, when the detected temperature is greaterthan the temperature threshold value, and a step of reducing the secondelectric power demanded from the second source to a value equal orsubstantially equal to the maximum operating power able to be suppliedby the second energy source, when the second electric power demandedfrom the second energy source exceeds the maximum operating power ableto be supplied by the second energy source.

The method may moreover comprise a step of adjusting the electric powerdemanded from the first energy source, such that the sum of the firstelectric power demanded from the first source and of the second electricpower demanded from the second source remains equal to a target electricpower intended to be supplied to the electric motor of the vehicle.

According to one optional feature of the method according to theinvention, the electric power demanded from the second energy sourceremains unchanged when the electric power demanded from the secondenergy source is less than the maximum operating power able to besupplied by the second energy source and/or when the detectedtemperature is lower than the temperature threshold value.

Other features and advantages of the invention will become more apparentfrom the following description, on the one hand, and from a plurality ofnon-limiting exemplary embodiments that are given by way of indicationwith reference to the appended schematic drawings, on the other hand, inwhich drawings:

FIG. 1 is a partial schematic view of an electric vehicle equipped withan electric power supply device according to the invention, able toimplement the method according to the invention;

FIG. 2 is a flowchart showing the various steps of one embodiment of themethod according to the invention;

FIG. 3 is a flowchart similar to that of FIG. 2 , illustrating thevarious steps of an alternative embodiment of the method according tothe invention;

FIG. 4 is a diagram illustrating one feature of the invention accordingto which, at a given time, two electric power sources for an electricmotor are controlled so as to modify the power that they respectivelycontribute while maintaining a constant target power.

It will first be noted that although the figures illustrate theinvention in a detailed manner with a view to implementation thereof,they may of course serve to better define the invention whereappropriate. It will also be noted that, in all the figures, elementsthat are similar and/or that perform the same function have beendesignated by the same reference numbers.

The electric vehicle 1, illustrated schematically in FIG. 1 , comprisesan electric motor 3 connected to at least one set of wheels 5 of theelectric vehicle 1, the connection between electric motor 3 and set(s)of wheels enabling the traction and/or propulsion of the vehicle.

The electric motor 3 is supplied with electric power via an electricalenergy supply device 6. As may be seen in FIG. 1 , the electric vehicle1 thus has an architecture in which the set of wheels 5, the electricmotor 3 and the power supply device 6 are arranged in series, theelectrical energy produced by the power supply device 6 being used tosupply power to the electric motor so that the latter has the powerneeded to drive the set of wheels 5. The current supplied by theelectric power supply device 6 is a DC current that is converted, by afirst converter 9, into an AC current suitable for the electric motor 3.

As will be detailed below, the electric power supply device 6 is specialin that it comprises at least two energy sources in parallel,respectively able to supply all or part of the electric power desiredfor the electric motor 3. The electric power supply device 6 comprisesin particular a first energy source 7, here taking at least the form ofa main battery 8, which is able to supply a first electric power P1 onthe basis of the control instruction given thereto, and a second energysource 31, here taking at least the form of a fuel cell 33, which isable to supply a second electric power P2 on the basis of the controlinstruction given thereto.

The main battery 8 is able to keep a quantity of electrical energy inreserve in order to supply same to the electric motor 3 when the needarises. The main battery 8 is for example a lithium-ion battery.

The first energy source 7 here furthermore comprises a service battery11 for the operation of auxiliaries 15, for example lighting devices,and/or computers 17 of the electric vehicle 1 and/or a heating device 61for a passenger compartment of the electric vehicle 1. The servicebattery 11 may in particular be recharged by the main battery 8 byconverting the high-voltage DC current, for example 330 V, from the mainbattery 8 into a low-voltage DC current, for example 14 V, using asecond converter 13.

The main battery 8 may be recharged by an external energy source 21, 23.An external energy source 21, 23 may be an AC current from a poweroutlet in a home 21 that has to be rectified using a third converter 25internal to the electric car 1. An external energy source 21, 23 mayalso be a DC current from a supercharger 23 that does not need to gothrough a converter.

As mentioned above, the electric power supply device 6 comprises, inparallel, the first energy source and a second energy source 31, actingas a range extender 31, capable here of recharging the main battery 8and also of contributing to the supply of electric power to the electricmotor instead of or in addition to the main battery 8.

The second energy source 31 comprises a fuel cell system 33, acompressor 37, at least one tank for a reducing fuel 39 and a coolingsystem 41. The fuel cell 33 is able to generate an electric power P2through oxidation between the oxygen present in the air and delivered bythe compressor 37 and the reducing fuel, for example hydrogen, containedin the tanks 39. The electric power P2 is then converted via an inverter35 so as to be able to be directed to the electric motor. If necessary,this electric power P2 may also be used to recharge the main battery 8of the electric vehicle 1.

The oxidation reaction that occurs in the fuel cell 33 generatescalories, which are evacuated by the cooling system 41. The coolingsystem 41 comprises a cooling liquid that flows in a loop in a pipe 43that transports the cooling liquid between the fuel cell system 33 and aheat exchanger 47. The flow of the refrigerant fluid in the coolingsystem 41 is regulated by a pump 45. The heat exchanger 47 allows therefrigerant fluid to discharge its calories through an exchange with theair outside the electric vehicle 1. It should be noted that the quantityof calories that are able to be discharged by the refrigerant fluid, andtherefore the cooling capacity for the fuel cell associated with thiscooling system, depends on the size of this heat exchanger and on theconfiguration of the area of the vehicle in which this heat exchanger ispositioned. By way of non-limiting example, the cooling capacity for thefuel cell may vary depending on the surface area of the exchange areaprovided by the heat exchanger and/or the size of the grille on thefront face of the vehicle that lets in air liable to pass through thisexchange area.

The electric power supply device 6 comprises at least one control module51 that is configured in particular to control the supply of power ofeach of the energy sources 7, 31 and to determine the contribution ofelectric power by each energy source in order to optimize the use ofeach source according to their range, in particular to obtain a targetelectric power P, that is to say the electric power needed by theelectric motor 3 so that it is able to drive the set of wheels 5 in theconditions desired by the driver or the electronics of the vehicle.

In order to be able to better control the operation of each of thesources 7, 31 so as ultimately to generate this target electric power P,the control module 51 is configured to receive, or to calculate itself,an evaluation of the needs of the electric motor in terms of electricpower to meet the driver's demands in terms of traction/propulsion ofthe vehicle, for example according to the position of the acceleratorpedal.

The control module 51 associated with the power supply device accordingto the invention comprises a plurality of sensors, not shown here andincluding for example a sensor for sensing the level of charge of themain battery or a sensor for sensing the operating state of the rangeextender.

The control module 51 is in particular configured to take thesequalitative or quantitative data into account so as to determine adistribution of the contributions of the first energy source 7 and ofthe second energy source 31 for generating the target electric power P.

In a first operating configuration, the control module, for example ifthe main battery 8 is fully charged and without this limiting theinvention, controls the first energy source 7 and the second energysource 31 such that the main battery 8 generates all of the targetelectric power P.

In a second operating configuration, the control module, for example ifthe main battery 8 is discharged and without this limiting theinvention, controls the first energy source 7 and the second energysource 31 such that the fuel cell 33 generates all of the targetelectric power P.

In a third operating configuration, the control module controls thefirst energy source 7 and the second energy source 31 such that each ofthe sources contributes, in line with a distribution defined by thecontrol module 51, to generating the target electric power.

In other words, regardless of the operating configuration implemented bythe control module, the sum of the values of the first electric powerP1, that is to say the electric power generated by the first electricalsource 7 of the power supply device 6, and of the second electric powerP2, that is to say the electric power generated by the second electricalsource 31 of the power supply device 6, is equal to the value of thetarget electric power P intended to be supplied to the electric motor 3.

According to the invention, a maximum operating electric power of thesecond energy source, otherwise called maximum operating power P_(max)in the remainder of the description, is loaded into the memory of thecontrol module 51. This maximum operating power P_(max) depends on thecooling capacity for the second energy source, in particular here forthe fuel cell 33, provided by the associated cooling system 41. Thememory of the control module 51 may thus be loaded with a single maximumoperating power value P_(max), it being understood that this value mayvary from one vehicle to another depending on the size of the coolingsystem associated with the second energy source.

Moreover, and as will be explained below, the memory of the controlmodule 51 may consist of a data table in which the maximum operatingpower P_(max) is associated with a temperature, so as to take intoaccount variable cooling performance depending on the temperature of theenvironment in which the cooling system 41 is immersed.

As will be described below, in particular with reference to FIG. 2 ,this maximum operating power P_(max) is specific to the invention inthat the electric power supply device 6 is able to adopt multipleconfigurations for controlling the energy sources 7, 31 depending onwhether or not this maximum electric power is exceeded by the initialoperation of the fuel cell. More specifically, the electric power supplydevice 6 for an electric motor of a motor vehicle is configured tocompare the value of the second electric power P2 with the value of themaximum operating power P_(max) able to be supplied by the second energysource, and then, when the second electric power P2 exceeds the maximumoperating power P_(max) able to be supplied by the second energy source31, to modify the controlling of the second source so as to reduce thevalue of the second electric power to a value substantially equal tothat of the maximum operating power P_(max), and finally accordinglymodify the controlling of the first source so as to increase the firstelectric power P1 supplied by the first energy source 7.

As an alternative or in addition, the trigger threshold value may be thetemperature. In the embodiment illustrated in FIG. 1 , the electricpower supply device 6 comprises a temperature sensor 52 and the controlmodule 51 is configured to retrieve a temperature value T_(ext) detectedby this sensor. It should be noted that, without departing from thecontext of the invention, the control module could be configured toretrieve a temperature value from a temperature sensor also housed onboard the vehicle for other purposes and not dedicated specifically tothe electric power supply device.

In the example illustrated, the temperature sensor is configured todetect the temperature outside the vehicle, it being understood that thetemperature detected by the sensor could be a temperature of the fuelcell or of another component of the second energy source.

The temperature value T_(ext) detected by the temperature sensor 52 mayin particular be used in the first application case, with the maximumpower P_(max) equal to a single value that is independent of thetemperature. It will be understood that, when the detected temperatureT_(ext) is low, the thermal integration of the fuel cell system makes itpossible to meet the cooling needs of the fuel cell system. Indeed, inthis case, with the defined size of the heat exchanger forming part ofthe cooling system and arranged in particular on the front face of thevehicle, the high temperature difference between the operatingtemperature of the fuel cell system and the detected temperature enableseffective cooling of the fuel cell system.

Conversely, when the outside temperature T_(ext) is high, the thermalintegration of the fuel cell system makes it possible to meet thecooling needs of the fuel cell system only partially. Indeed, in thiscase, with the defined size of the heat exchanger forming part of thecooling system and arranged in particular on the front face of thevehicle, the temperature difference between the operating temperature ofthe fuel cell system and the detected temperature T_(ext) is small, andthe cooling system installed in the vehicle no longer enables effectivecooling of the fuel cell system. There is therefore a temperaturethreshold value T_(max) at which the cooling circuit still makes itpossible to cool the fuel cell system and beyond which the thermal powerable to be evacuated by the cooling system is limited, and therefore theelectric power generated by the fuel cell system must also be limited tothe level of the maximum operating power P_(max) able to be supplied bythe second energy source P2 _(max).

In each of the cases mentioned above, and regardless of the thresholdvalue under consideration, whether or not the temperature is taken intoaccount, for example, the power supply device 6 is configured to allow amethod for supplying an electric power that makes it possible, ifnecessary, to modify a first configuration Cfg1 for controlling theenergy sources, if this involves challenging conditions for cooling thesecond energy source 31 and in particular the fuel cell 33 liable to befitted to this second source.

One example of a method, according to a first embodiment, will now bedescribed with reference to the flowchart illustrated in FIG. 2 . Themethod is implemented, in the illustrated embodiment, by the controlmodule 51 of the electric vehicle 1.

The method according to the first embodiment 100 may be initiated by arequest for electric power 101 from the electric motor. This request maybe sent in the direction of the control module 51, or else the controlmodule is configured to go and retrieve operating data from the vehicle,for example an acceleration demand made by the driver, to generate thisrequest.

This request is analyzed by the control module 51 so as to define, in acalculating step 110, a first control configuration Cfg1 in whichoperating instructions are generated for each of the energy sources 7,31. As was described above, the sum of the values of the electric powerP1, P2 generated by the operation of each energy source 7, 31 is equalto a target electric power P, that is to say an overall value ofelectric power intended to be supplied to the electric motor. In theexample described here, this target electric power P is equal to 100% ofthe electric power supplied to the electric motor, without this limitingthe invention, since the quantity of power supplied by the two energysources remains constant when transitioning from one controlconfiguration mode to the other.

At the same time as the generation of the control instructions for theenergy sources 7, 31, or at the end of a given time period, without thislimiting the invention, the supply method according to the inventioncomprises a phase of modifying the controlling of the energy sources.

In the first embodiment, the phase of modifying the controlling of theenergy sources begins with a step 120 of comparing electric power,between the power demanded from the second energy source 31 in the firstcontrol configuration Cfg1 and the maximum operating power P_(max).

To this end, in a data retrieval step 115, the control module 51retrieves the maximum operating power value P_(max) from the memoryprovided for this purpose and considers the electric power demanded fromthe second energy source 31 in the first control configuration Cfg1. Inone variant of this first embodiment of the method, and as shown indotted lines in FIG. 2 , the datum retrieved as maximum operating powervalue P_(max) may depend on the temperature, considering that thedetected temperature T_(ext) or the temperature released by the fuelcell system may impact the cooling function. In this variant, an ambienttemperature T_(ext), or a temperature of the environment close to thecooling system, may be retrieved by the control module 51 so as toretrieve, from the database, and in this case from a data table, amaximum power value adjusted to the detected temperature.

If the result of this comparison step 120 is such that the value ofelectric power P2 demanded from the second energy source in the firstcontrol configuration Cfg1 is lower than the value of the maximumoperating power P_(max), the power demanded from each of the energysources, and in particular from the fuel cell forming the second energysource, remains unchanged and the first control configuration Cfg1 isretained.

Conversely, if the value of electric power P2 demanded from the secondenergy source in the first control configuration is greater than thevalue of the maximum operating power P_(max), the control module 51generates a modification of the control instructions for the energysources 7, 31 so as to modify their contribution of electric powerwithout penalizing the supply of power to the electric motor 3.

More specifically, the control module sends an instruction 130 to reducethe electric power demanded from the second energy source 31, such thatthis second electric power P2 is reduced to the level of the maximumoperating power value P_(max). This thus ensures that the cooling willbe carried out correctly during operation of the fuel cell system andthat it will be able to work correctly.

At the same time, the control module, in an adjustment step 140, sendsan instruction to increase the electric power demanded from the firstenergy source so as to maintain the target electric power. The methodthus provides a step of adjusting the electric power P1 demanded fromthe first energy source 7 on the basis of the modification that has beenmade to the electric power P2 demanded from the second energy source 31,in order to maintain the target electric power P.

In other words, the control module 51 modifies the control instructionsgiven to the two energy sources such that they are controlled in asecond control configuration Cfg2 different from the first controlconfiguration Cfg1, but with a value of electric power delivered to themotor by the power supply device that remains unchanged, this value ofelectric power delivered to the motor by the power supply device beingequal to the sum of the values of the first electric power P1, that isto say the electric power generated by the first electrical source 7 ofthe power supply device 6, and of the second electric power P2, that isto say the electric power generated by the second electrical source 31of the power supply device 6.

FIG. 3 illustrates a second embodiment of the method according to theinvention, which differs from what has been described above in that thestep of comparing the demanded electric power with the maximum operatingpower P_(max) is initiated based on a temperature detected by atemperature sensor.

This second embodiment 200 thus comprises, after the step 110 ofcalculating the first control configuration in accordance with what hasbeen described above, a step 210 of comparing the detected temperatureT_(ext) with a temperature threshold value T_(max), the result of thisstep possibly leading to the first control configuration Cfg1 beingmaintained or to the starting of a phase of modifying the controlling ofthe sources in accordance with what has been described above so as toobtain a second control configuration Cfg2. In a manner similar to whathas been mentioned above for the maximum operating power value, thetemperature threshold value T_(max) may be retrieved by the controlmodule 51 from an appropriate memory, during a data retrieval step 215.In other words, the power comparison carried out by the control module51 as was mentioned above remains the same, but is performed, in thissecond embodiment, only when the detected temperature T_(ext), exceeds atemperature threshold value T_(max).

To implement this second embodiment of the method 200, a temperaturevalue should be able to be detected and the power supply device 6, tothis end, may comprise a temperature sensor 52, it however beingunderstood that the temperature value could also be retrieved from themanagement electronics of the vehicle. The temperature underconsideration here may in particular be the ambient temperature, outsidethe vehicle, or else be the temperature in the area of the substructureof the vehicle in which the fuel cell system is primarily arranged.

Given that the outside temperature T_(ext), or the temperature of theenvironment close to the fuel cell system, is taken into account priorto the phase of modifying the controlling of the sources, the maximumoperating power P_(max), retrieved in the data retrieval step 115, isindependent here of the detected temperature.

It should be understood from the description of this second embodimentof the supply method that it has a purpose similar to that of the firstembodiment, with the obtaining of a second control configuration Cfg2,different from the first control configuration Cfg1, when a detectedvalue is greater than an operating threshold value.

FIG. 4 illustrates the transition from one control configuration to theother, in particular in the case where the method for supplying electricpower takes into account the exceedance of a temperature threshold valueso as to initiate the modification of the control configurations, toillustrate the fact that the sum of the values of electric powerrespectively supplied by the first and the second energy source remainsthe same in the first configuration and in the second configuration.

More specifically, in the first configuration Cfg1, here when thedetected temperature T_(ext) is lower than the threshold temperatureTmax, the first energy source is controlled so as to generate a firstelectric power P11 and the second energy source is controlled so as togenerate a second electric power P21. The value of the first electricpower P11 and the value of the second electric power P21 are such thattheir sum is equal to the value P of the electric power delivered by thepower supply device 6 to the electric motor 3.

At the time of transitioning from one configuration to the other, herewhen the detected temperature T_(ext) is equal to the thresholdtemperature value T_(max), and because the electric power demanded fromthe second source in the first configuration is greater than the maximumoperating power P_(max), the second energy source is controlled so as tobring the generated electric power back to a value equal to the maximumoperating power P. At the same time, the first energy source iscontrolled so as to generate a first electric power P12 of a valuegreater than that of the first electric power P11 of the firstconfiguration, so as to compensate for the reduction in power generatedby the second control configuration of the second energy source. In thiscase too, in this second configuration, the value of the first electricpower P12 and the value of the second electric power, here equal to themaximum operating power P_(max), are such that their sum is equal to thevalue P of the electric power delivered by the power supply device 6 tothe electric motor 3.

The invention as has just been described achieves the aim that it setitself, and makes it possible to propose a method for supplyingelectrical energy to a motor of an electric vehicle, making it possibleto optimize the operation of two energy sources that are able to supplyelectric power to an electric motor in parallel. In particular, thisinvention makes it possible to extend the range of a motor vehiclewithout penalizing the electric power that needs to be delivered to theelectric motor so that the latter is able to provide the performancedesired by the driver of the vehicle, and without risking creating amalfunction of the additional energy source forming a range extender. Ofcourse, the invention is not limited to the examples that have just beendescribed and many modifications may be made to these examples withoutdeparting from the scope of the invention.

1-10. (canceled)
 11. An electric power supply device for an electric motor of a motor vehicle, comprising at least one first energy source; at least one second energy source; and a control module configured to control the first energy source so as to supply a first electric power and to control the second energy source so as to supply a second electric power, wherein the control module comprises a memory module configured to store a value of a maximum operating power able to be supplied by the second energy source, the maximum operating power value being dependent on a cooling capacity for the second energy source.
 12. The electric power supply device as claimed in claim 11, wherein the control module is configured to: compare a value of the second electric power with the value of the maximum operating power able to be supplied by the second energy source, modify, when the second electric power exceeds the maximum operating power able to be supplied by the second energy source, the control of the second source so as to reduce the value of the second electric power to a value substantially equal to that of the maximum operating power able to be supplied by the second energy source, and modify the control of the first source so as to increase the first electric power supplied by the first energy source.
 13. The electric power supply device as claimed in claim 11, wherein a sum of values of the first electric power and of the second electric power is equal to a target electric power to be supplied to the electric motor.
 14. The electric power supply device as claimed in claim 11, wherein the first energy source comprises at least one electric battery and/or wherein the second energy source comprises at least one fuel cell.
 15. The electric power supply device as claimed in claim 11, further comprising at least one temperature sensor, wherein the control module is configured to compare a detected temperature with a temperature threshold value, the electric power supply device being configured to modify the control of the first and second energy sources when the detected temperature exceeds the temperature threshold value.
 16. The electric power supply device as claimed in claim 11, further at least one temperature sensor, wherein the value of the maximum operating power able to be supplied by the second energy source is variable based on a detected temperature.
 17. A motor vehicle comprising: an electric motor; and the electric power supply device as claimed in claim
 11. 18. A method for supplying an electric power demanded by the electric power supply device for an electric motor as claimed in claim 15, the method comprising: comparing the detected temperature with a temperature threshold value; comparing the second electric power demanded from the second energy source and the maximum operating power able to be supplied by the second energy source, when the detected temperature is greater than the temperature threshold value; and reducing the second electric power demanded from the second source to a value equal or substantially equal to the maximum operating power able to be supplied by the second energy source, when the second electric power demanded from the second energy source exceeds the maximum operating power able to be supplied by the second energy source.
 19. The method as claimed in claim 18, further comprising adjusting the electric power demanded from the first energy source, such that a sum of the first electric power demanded from the first source and of the second electric power demanded from the second source remains equal to a target electric power to be supplied to the electric motor of the vehicle.
 20. The method as claimed in claim 18, during which the second electric power demanded from the second energy source remains unchanged when the electric power demanded from the second energy source is less than the maximum operating power able to be supplied by the second energy source and/or when the detected temperature is lower than the temperature threshold value. 